• 한국환경과학회지
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• 제20권2호
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• pp.163-174
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• 2011

Butyltin compounds in seawater, sediments and organisms inside Jeju Harbor of Jeju Island, Korea, were quantitatively determined to assess the extent of contamination and to evaluate the bioaccumulation in Thais clavigera (gastropod), Liolophura japonica and Cellana nigrolineata. In addition, imposex in T. clavigera was used to assess the sublethal effect of tributyltin compounds and its usage as a specific biomarker for these compounds was also studied. The main species in seawater was tributyltin (TBT) in March and June, monobutyltin (MBT) in August, but in sediments and organisms it was dibutyltin (DBT) and TBT, respectively, irrespective of survey time. TBT, the most toxic to aquatic organisms among BTs, was found at concentrations which were sufficient to have a serous effect on the sensitive organisms upon chronic exposure. The high correlations (r>0.7) between BTs indicated that DBT and MBT were mainly degraded from TBT based on antifouling paints and their sources were negligible. The sedimentary organic matters have little influence on the distribution of BTs in marine environment and the lipid content in T. clavigera showed a significant correlation with TBT concentrations. Measurement of imposex T. clavigera was expected to be a very helpful tool for preliminary survey of BTs prior to trace analysis of those.

• Animal Systematics, Evolution and Diversity
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• 제27권1호
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• pp.1-17
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• 2011

Thais Roding, 1798, commonly known as rock-shell, is among the most frequently found gastropod genera worldwide on intertidal rocky shores including those of Japan, China, Taiwan and Korea. This group contains important species in many marine environmental studies but species-level taxonomy of the group is quite complicated due to the morphological variations in shell characters. This study examined the genetic variations and relationships among three Korean Thais species based on the partial nucleotide sequences of mitochondrial cox1 gene fragments. Phylogenetic trees from different analytic methods (maximum parsimony, neighbor-joining, and maximum likelihood) showed that T. bronni and T. luteostoma are closely related, indicating the most recent common ancestry. The low sequence divergence found between T. luteostoma and T. bronni, ranging from 1.53% to 3.19%, also corroborates this idea. Further molecular survey using different molecular marker is required to fully understand a detailed picture of the origin for their low level of interspecific sequence divergence. Sequence comparisons among conspecific individuals revealed extensive sequence variations within the three species with maximum values of 2.43% in T. clavigera and 1.37% in both T. bronni and T. luteostoma. In addition, there is an unexpectedly high level of mitochondrial genotypic diversity within each of the three Korean Thais species. The high genetic diversity revealed in Korean Thais species is likely to reflect genetic diversity introduced from potential source populations with diverse geographic origins, such as Taiwan, Hong Kong, and a variety of different coastal regions in South China and Japan. Additional sequence analysis with comprehensive taxon sampling from unstudied potential source populations will be also needed to address the origin and key factors for the high level of genetic diversity discovered within the three Korean Thais species studied.

• 한국환경과학회지
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• 제9권4호
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• pp.285-294
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• 2000

Butyltin compounds (BTs) in seawater, sediments and organisms (Thais clavigera, Liolophura japonica and Cellana nigrolineata), were quantitatively determined to evaluate their distribution inside Songsan Harbor of Cheju Island. In addition, imposex in T. clavigera was used to assess the effect on organisms of BTs. Analysis of the samples collected in seawater, sediments (March, June and August) and organisms (May, July and August) in 1998, confirmed the contamination of BTs in the aquatic environment inside Songsan Harbor. The main BTs species in seawater and sediments was monobutyltin (MBT), tributyltin (TBT), respectively, irrespective of survey time. In oranisms, TBT and dibutyltin (DBT) were detected in similar concentrations for T. clavigera and L. japonica, but for C nigrolineata, DBt concentration was the highest. TBT, the most toxic to aquatic organisms among BTs, was found at concentrations which were sufficient to have a serious effect on the sensitive organisms upon chronic exposure, The relatively high correlations (r>0.83) between BTs indicated that DBT and MBT were mainly degraded from TBT based on antifouling paint and their sources were negligible. The sedimentary organic matters did not have influence on the distribution of BTs in marine environment, and lipid content in T. clavigera did not show a correlation with TBT concentrations. The rate of occurrence of imposex in T. clavigera was 100%, and the relative penis length index (RPLI) and the relative penis size index (RPSI) which represent the degree of imposex were 79.7%, 58.1%, respectively. Measurement of imposex in T. clavigera was expected to be a very helpful tool for preliminary survey of BTs prior to trace analysis of BTs.

• 한국어업기술학회:학술대회논문집
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• 한국어업기술학회 2000년도 춘계수산관련학회 공동학술대회발표요지집
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• pp.375-376
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• 2000

Sex ratio of a population is a key factor to determine reproductive rate of the population. If the population has skewed sex ratio to the male, the population size may decline gradually at an area which it inhabits, and, furthermore, if a species plays an ecologically important role in its community (e.g., a keystone species in Paine, 1966), its potential reproductive rate will be to form a characterized community because community structure is strongly influenced by the abundance of the ecologically important species (Hughes, 1986). A number of workers (e.g., Bryan et al., 1986 in Nucella lapillus; Spence et al., 1990 in Thais haemastoma) suggested that high frequency and/or late stage of imposex might affect the female mortality and normal reproduction adversely. Consequently, the imposex could affect sex ratio of natural population of some neogastropod including thaisid species. (omitted)

• 환경생물
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• 제22권
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• pp.63-70
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• 2004

Tributyltin (TBT) and its degradation products, dibutyltin (DBT) and monobutyltin (MBT) were quantitatively determined in surface sediments and two molluscan species, Pacific oyster (Crassostrea gigas) and rock shell (Thais ctavigera), from Gwangyang Bay, Korea. Butyltin compounds were detectable in almost all sediment and biota samples. Tributyltin concentrations in surface sediment ranged<2∼33 ng g$\^$-1/, which is at a lower end of TBT concentrations in industrialized bays in Korea. However, TBT levels in sediments were related to boating activities around the bay. In biota samples, TBT concentrations were in the range of 178∼2,458 ng g$\^$-1/ toy oyster and 47∼236 ng g$\^$-1/ for rock shell. Relatively high TBT concentrations in biota were found near wharves for fisherboats and harbor areas. About 90∼100％ of the female T. clavigera displayed imposex, and relative penis length index of the imposexed-female was in the range of 20.9∼107.9％. Furthermore, TBT body residue had a significant positive relationship with degree of imposex in T. clavigera. Overall, TBT concentrations in Gwanyang Bay were much lower than other major bays in Korea.

• 약학회지
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• 제37권5호
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• pp.527-531
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• 1993

As a part of chemical study on the bioactive metabolites from marine organisms, we have investigated cytotoxicity using brine shrimp bioassay for each solvent fractions of the marine algae(12 species), marine sponges(3 species), coelenterates(2 species), echinoderms(4 species), marine molluscs(17 species), and ascidians(2 species), respectively. As the results, chloroform extract of Stichopus japonicus (LC$_{50}$ : 274 $\mu\textrm{g}$/ml), ethyl acetate extract of Anthocidaris crassispina(LC$_{50}$ : 121 $\mu\textrm{g}$/ml), n-butanol extract of Unda), ia Pinnatifida (LC$_{50}$ : 178 $\mu\textrm{g}$/ml), and water extract of Thais clavigera (LC$_{50}$ : 61 $\mu\textrm{g}$/ml) displayed the most significant cytotoxic activity against brine shrimp. Among the marine organisms tested, echinoderms and marine molluscs were thought to be the most active Phylums on screening of new bioactive compounds.

• 한국해양환경ㆍ에너지학회지
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• 제12권3호
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• pp.157-164
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• 2009

슬래그 매립장 배출구 인근해역에 곰피(Ecklonia stolonifera)를 이식한 소규모 인공해조장을 건설하여 해조장에서 서식하는 저서생물 군집의 천이 양상을 2004년 4월부터 2005년 6월까지 모니터링 하였다. 첫 번째 이식 후 조사(2004년 4월부터 10주간 실험)에서는 솜말(Acinetospora critina)이 인공해조장에서 가장 우점하였다. 두 번째 조사(2004년 6월 이식 후 51주간 실험)에서는 총 15종의 해조류가 발견되었는데, 이 중 창자파래(Enteromorpha intestinalis)와 파래류(Enteromorpha sp.)가 가장 우점하였다. 그 외 초록털말(Urospora penicilliformi), 초록실(Ulothrix flacca), 대마디말류(Cladophora sp.), 그리고 구멍갈파래(Ulva pertusa)가 곰피의 잎에 나타났다. 동시에 곰피의 잎에 부착하여 서식하는 저서동물, 연체동물 그리고 작은 크기의 어류 등도 출현하였다. 부착 저서동물은 주로 단각류(Amphipods)였으며, 연체동물은 진주담치(Mytilus edulis), 대수리(Thais clavigera), 그리고 어류는 숭어(Mugil cephalus), 베도라치(Pholis nebulosa) 등이 우점하였다. 이와 같은 결과는 곰피를 이용하여 조성된 인공해조장이 생물들이 성장할 수 있는 서식처 역할을 수행함과 동시에 스스로의 천이 과정을 통하여 저서생물 군집이 형성되는데 기여하였음을 알 수 있다.

• 한국패류학회지
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• 제26권4호
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• pp.317-326
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• 2010

The availability of fast and inexpensive sequencing technology has enabled researchers around the world to conduct many genome sequencing and expressed sequence tag (EST) projects of diverse organisms. In recent years, whole genome projects have been undertaken to sequence ten species from the phylum Mollusca. These include Aplysia californica, Lottia gigantea, Crassostrea virginica, Spisula solidissima, Mytilus californianus, Biomphalaria glabrata, Crepidula fornicata, Elysia chlorotica, Lottia scutum and Radix balthica. Additionally, complete mitochondrial genomes of 91 mollusks have been reported. In Korea, EST projects have been conducted in nine mollusk species that include Nesiohelix samarangae, Pisidium (Neopisidium) coreanum, Physa acuta, Incilaria fruhstorferi, Meretrix lusoria, Ruditapes philippinarum, Nordotis gigantea, Crassostrea gigas and Laternula elliptica. Finally, the mitochondrial genome projects from the Pacific Oyster (Crassostrea gigas) and the rock shell (Thais clavigera) have been conducted and reported. However, no systemic mollusk genome project has so far been conducted in Korea. In this report, the current status and research trends in mollusk genome study in Korea will be discussed.

• Molecular & Cellular Toxicology
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• 제3권1호
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• pp.1-10
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• 2007

The persistent and ubiquitous environmental contaminant, tributyltin chloride (TBT), induces not only imposex in gastropods but also the differentiation of adipocytes in vitro and increases adipose mass in vivo in vertebrates. TBT is a nanomolar affinity ligand for retinoid X receptor (RXR) in the rock shell(Thais clavigera) and for both the RXR and the peroxisome proliferator activated receptor $\gamma(PPAR\gamma)$ in the amphibian (Xenopus laevis), mouse, and human. The molecular mechanisms underlying induction of imposex by TBT have not been clarified, though several hypotheses are proposed. TBT promotes adipogenesis in the murine 3T3-L1 cell model and perturbs key regulators of adipogenesis and lipogenic pathways in vivo primarily through activation of RXR and $PPAR\gamma$. Moreover, in utero exposure to TBT leads to strikingly elevated lipid accumulation in adipose depots, liver, and testis of neonate mice and results in increased adipose mass in adults. In X. laevis, ectopic adipocytes form in and around gonadal tissues following organotin, RXR or $PPAR\gamma$ ligand exposure. TBT represents the first example of an environmental endocrine disrupter that promotes adverse effects from gastropods to mammals.